The invention relates to an interface between a production management system (MES, for Manufacturing Execution System) and an automation system, and to a method for operating such an interface, in accordance with claims 1 and 15, respectively.
The predestined interface for exchanging information between software applications was known as Dynamic Data Exchange (DDE). Now, OPC has become established as the standardized interface for exchanging process data in PC-based automation technology. OPC is an application of Microsoft's DCOM (Distributed Component Object Model) technology. Compared to the DDE interface, the OPC-based data exchange is distinguished by significantly better performance. If an automation system is equipped with an OPC server, then secure communication with higher-order monitoring systems can be achieved as a result. Since in many automation system components there is no standardized communication interface, linking this communication interface to an MES by the user involves major programming effort, because the commands, furnished by the automation system component, for parametrizing the component have to be converted into a format that can be read and written by the MES. Alternatively, the MES vendor could simultaneously supply a component-specific link too. Then, however, the MES system is inflexible, and the automation system components cannot be replaced by components from other manufacturers except at major programming effort. For the manufacturer of the production management system as well, the effort and expense are higher, since the vendor has to ship different interface modules to his customers for different automation components.
German Utility Model DE 202 80 020 U1 discloses a welding tool with an OPC server and a data processing program for converting internal data from the welding tool from an internal data format to the OPC standard format and/or vice versa. The OPC server includes measurement/output means for acquiring internal data, and the OPC server is in communication with an OPC interface, and the OPC interface is located on a housing of the welding tool. The welding tool can be exchanged very easily for welding tools from other manufacturers who also use the OPC standard format. By means of the measurement/output means, the OPC server can acquire internal operating states of the welding tool, and by means of the OPC interface OPC can prepare them conformally and forward them, but the higher-order system (such as MES) is required for evaluating the data.